Derivatives (Summary Of Derivative Instruments Contracts) (Details) | Jun. 30, 2017MMBTU$ / MMBTU$ / bblbbl | Sep. 30, 2016MMBTU$ / MMBTU$ / bblbbl |
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 200,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 2.80 | 1.95 |
Natural Gas Costless Collars [Member] | Derivative Contract Period One [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.47 | 2.40 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Two [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 70,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Two [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3 | 2.75 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Two [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.35 | 3.05 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Three [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 50,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Three [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 2.80 | 2.90 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Three [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.35 | 3.40 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Four [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 50,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Four [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 2.75 | 2.25 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Four [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.35 | 3.65 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Five [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 30,000 | 80,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Five [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3 | 2.25 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Five [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.65 | 3.95 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Six [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 50,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Six [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3 | 2.60 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Six [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.60 | 3.25 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Seven [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 50,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Seven [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.20 | 2.85 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Seven [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.65 | 3.35 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Eight [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 100,000 | 50,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Eight [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.50 | 2.80 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Eight [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.95 | 3.47 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Nine [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 150,000 | 50,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Nine [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.40 | 3 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Nine [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.95 | 3.35 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Ten [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 40,000 | 50,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Ten [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | 2.75 | 2.80 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Ten [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | 3.35 | 3.35 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Eleven [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | | 50,000 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Eleven [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | | 2.75 |
Natural Gas Costless Collars [Member] | Derivative Contract Period Eleven [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | | 3.35 |
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Eleven [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 25,000 | |
Contract price | 3.100 | |
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Twelve [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 100,000 |
Contract price | 3.070 | 2.410 |
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Thirteen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 25,000 |
Contract price | 3.210 | 3.200 |
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Fourteen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 30,000 | 80,000 |
Contract price | 3.300 | 2.955 |
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Fifteen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 25,000 |
Contract price | 3.510 | 3.100 |
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Sixteen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 50,000 | 50,000 |
Contract price | 3.700 | 3.070 |
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Seventeen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 75,000 | |
Contract price | 3.575 | |
Natural Gas Fixed Price Swaps [Member] | Derivative Contract Period Eighteen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Natural Gas | MMBTU | 100,000 | |
Contract price | 3.520 | |
Oil Costless Collars [Member] | Derivative Contract Period Seventeen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Oil | bbl | | 3,000 |
Oil Costless Collars [Member] | Derivative Contract Period Seventeen [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | | 35 |
Oil Costless Collars [Member] | Derivative Contract Period Seventeen [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | | 49 |
Oil Costless Collars [Member] | Derivative Contract Period Eighteen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Oil | bbl | | 3,000 |
Oil Costless Collars [Member] | Derivative Contract Period Eighteen [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | | 40 |
Oil Costless Collars [Member] | Derivative Contract Period Eighteen [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | | 47.25 |
Oil Costless Collars [Member] | Derivative Contract Period Nineteen [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Oil | bbl | 3,000 | 3,000 |
Oil Costless Collars [Member] | Derivative Contract Period Nineteen [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 50 | 40 |
Oil Costless Collars [Member] | Derivative Contract Period Nineteen [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 55 | 58.50 |
Oil Costless Collars [Member] | Derivative Contract Period Twenty [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Oil | bbl | 3,000 | 3,000 |
Oil Costless Collars [Member] | Derivative Contract Period Twenty [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 52 | 45 |
Oil Costless Collars [Member] | Derivative Contract Period Twenty [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 58 | 54 |
Oil Costless Collars [Member] | Derivative Contract Period Twenty One [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Oil | bbl | 3,000 | 3,000 |
Oil Costless Collars [Member] | Derivative Contract Period Twenty One [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 53 | 45 |
Oil Costless Collars [Member] | Derivative Contract Period Twenty One [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 57.75 | 55.50 |
Oil Costless Collars [Member] | Derivative Contract Period Twenty Two [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Oil | bbl | 2,000 | |
Oil Costless Collars [Member] | Derivative Contract Period Twenty Two [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 50 | |
Oil Costless Collars [Member] | Derivative Contract Period Twenty Two [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 57.50 | |
Oil Costless Collars [Member] | Derivative Contract Period Twenty Three [Member] | | |
Derivative [Line Items] | | |
Production volume covered per month - Oil | bbl | 5,000 | |
Oil Costless Collars [Member] | Derivative Contract Period Twenty Three [Member] | Minimum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 45 | |
Oil Costless Collars [Member] | Derivative Contract Period Twenty Three [Member] | Maximum [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 56.25 | |
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Four [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 53.89 | |
Production volume covered per month - Oil | bbl | 3,000 | |
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Five [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 54.20 | |
Production volume covered per month - Oil | bbl | 2,000 | |
Oil Fixed Price Swaps [Member] | Derivative Contract Period Twenty Six [Member] | | |
Derivative [Line Items] | | |
Contract price | $ / bbl | 54 | |
Production volume covered per month - Oil | bbl | 4,000 | |